447138221 has 2 divisors, whose sum is σ = 447138222. Its totient is φ = 447138220.

The previous prime is 447138161. The next prime is 447138259. The reversal of 447138221 is 122831744.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 446857321 + 280900 = 21139^2 + 530^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-447138221 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (447138121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 223569110 + 223569111.

It is an arithmetic number, because the mean of its divisors is an integer number (223569111).

Almost surely, 2^447138221 is an apocalyptic number.

It is an amenable number.

447138221 is a deficient number, since it is larger than the sum of its proper divisors (1).

447138221 is an equidigital number, since it uses as much as digits as its factorization.

447138221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10752, while the sum is 32.

The square root of 447138221 is about 21145.6430736925. The cubic root of 447138221 is about 764.6815260572.

Adding to 447138221 its reverse (122831744), we get a palindrome (569969965).

The spelling of 447138221 in words is "four hundred forty-seven million, one hundred thirty-eight thousand, two hundred twenty-one".